Starting problem/Rotostart issue/one way bearing stuck?

[Teeds]

Hi,

I bought a Savage X 4.6 (2011/2013 i think, it has the big bore shocks and the pistol-grip style rotostart) a few months ago.

I did the break in following the manual's instructions but always had a problem starting it. It was always the same thing, hard to make the engine turn over to start it. The symptoms were ones of a flooded engine except it was not, I made sure I checked every time. I tried different plugs, different glow igniters, different settings on the rotostart and eventually got it to start by leaning the high speed needle a bit and slightly unscrewing the glow plug until it fired. But the problem seemed to remain that the rotostart would almost never be able to make more than one or two rotations before disengaging.

..7-8 tanks in...

There seems to be an issue with the starting mechanism in the backplate of the engine. The rotostart keeps disengaging and doesn't turn the engine over. I thought the engine might be damaged but I managed to start it with a drill (battery and clutch set at minimum) in a second. Then I tried the rotostart on its own and it seemed to work okay. However, when I inspected the starting assembly on the engine by turning the starting shaft (rod(#87617) that connect the rotostart to the back plate set (#109535), I find it really hard to turn at some point and this is after the compression "pops". I mean, I can turn the rod by hand until it becomes very hard (after the two hard to turn phases of a normal engine!), but then with the other hand I can freely turn the flywheel some more. Kind of like it's not the engine that's hard to turn but the backplate cup joint. If I turn it counter clockwise, it also hangs at one point. Shouldn't this be turning freely going counter clockwise and turn the engine going clockwise? It makes a small metallic "ting" noise when it finally starts getting easier to turn.

Is this something that's normal for that kind of one way bearing? I was told by HPI that new engines are hard to turn but it really seems to be something else. Should I take everything appart or keep starting it with a drill? What do you guys think?

Thanks!

 

[BIRDMAN]

is this truck brand new form a hobby store??

 

[HPIguy]

Try backing the glow plug out about a 1/4 turn, once it's running you can snug it back up. Even my old Savage 25 would eat one ways in the Roto start, or simply not start at all unless I did this.

 

[Teeds]

Wow thanks for the quick replies guys!

1-Yes, the truck was bought brand new from a hobby store... but it's really far and between us, I'd really like to have the satisfaction of fixing it myself!

2-Strange thing is, even with the glow plug completely out (I can see the cylinder moving up and down), it's still harder to turn the backplate/one way bearing/roto-shaft than the engine itself. But maybe that's normal and it's how it is, but it simply doesn't sound and feel right (when turning it by hand)!


Some notes:
A- I did not take the engine apart yet, I was hopping there was a simple solution like WD-40 in the backplate engine to help loosen it up (did not work). I heard that you might need a few o-rings and washers when disassembling the engine because they are super thin and do not last long. I'd also like to be able to exchange it if something is wrong so the less I break it apart the better for now.

That being said, I am not afraid of getting my hands dirty if needed!

B- I've owned two other nitro RCs for about three months, they are both Redcat Racing (Volcano S30 and Shockwave) that I got used. They were complete crap but I've learned so much from rebuilding them that I think I got a good idea of whats going on in a nitro rc and engine.

Both have that hex-like one way bearing, not like the one in the Savage X 4.6 (part #15136).

C*IMPORTANT*- I can start the Savage almost anytime I want if I use my drill but if the one way bearing (if it's even called a bearing because it seems like another kind of mechanism) can't turn freely while going reverse, does it mean the engine has to work harder to overcome this as it runs? Maybe that's why I can't pull off wheelies or get to second gear? (Although that's probably because I didn't have enough runs to tune it properly). That being said, it runs, in my eyes, pretty well and the only thing regardless of starting that makes me think something is wrong is that "cling" noise is makes when it runs out of gas...


So I guess in a nutshell: I can start my Savage but not with the rotostart (will not even turn the engine more than once and get stuck) and I am afraid of breaking the engine because of that "something" odd in the back plate starting assembly that hangs. Are my fears confirmed? Should I take it apart or to the store? Are there any steps to diagnose the problem?

Thanks again guys, I really appreciate your help!

 

[BillyC74]

It's not a one way bearing. Hpi just change the starting system on the x. I don't have one but the way I understand it, it no longer uses a owb. There are some set screws on the part that the roto start wand plugs into. Take those out and loctite then back it. A lot of guys are using the drill method to start the truck so no worries there.

 

[BIRDMAN]

Does he rotostart have a full charge???

 

[sur3fir3]

personally the starter systems are more trouble than they are worth. I always just get a pullstart. Many people love the electric starters, but unless it uses a bump box, I just get a pullstart for it.

 

[Nitro robbo]

personally the starter systems are more trouble than they are worth. I always just get a pullstart. Many people love the electric starters, but unless it uses a bump box, I just get a pullstart for it.

Yeah i agree.get a pull start.I've been told to avoid the roto starts because you can't tell if your motor is flooded.

 

[Teeds]

Thanks!

Yeah i agree.get a pull start.I've been told to avoid the roto starts because you can't tell if your motor is flooded.

personally the starter systems are more trouble than they are worth. I always just get a pullstart. Many people love the electric starters, but unless it uses a bump box, I just get a pullstart for it.

Yea I think that if I find anything wrong with the rotostart backplate assembly, I'll order in a pullstart as backup as well, it's what I'm mostly used to anyway.

Does he rotostart have a full charge???

Yes, always fully charged. The rotostart motor turns but the "clutch" doesn't grab as if the engine is flooded..which it is not, it does it even without fuel, unplugged lines and engine drained from anything. Only by removing the glow plug (turn or more) can the rotostart finally turn the engine normally.

It's not a one way bearing. Hpi just change the starting system on the x. I don't have one but the way I understand it, it no longer uses a owb. There are some set screws on the part that the roto start wand plugs into. Take those out and loctite then back it. A lot of guys are using the drill method to start the truck so no worries there.

Yes, I checked the manual and it seems to be some sort of pressure pin (HPI Starting PinPressure Spring .21BB HPI1433) that connects the starting shaft and crank shaft.

Turning it by hand. it feels like the pin might have got out and the spring is still stuck in there making it hard to turn...or the pin could be damaged and rubbing on something.

I'll rip the engine apart from the backplate when I'll have time and post my findings.

Thanks guys!

 

[Teeds]

Update to the starting problems...

So, I took the Savage appart for cleaning and while I was there tried to fix the starting problem...

It seemed someone was right!! The set screws on the rotostart shaft were the culprits. When I opened it, one set screw was just lying there, half grinded and without most of it's thread left...the other one was still in but barely.

So yeah I hope that was the problem, fixed it, now the engine will turn with the rotostart assembly. That does not mean the engine is easier to turn though, it's still impossible for the rotostart to do anything else than whine and try but with a drill, it starts anytime.

Someone told me the engine, when new, could be really hard to turn but I'm starting to wonder if I shouldn't add a washer to the glow plug (so there would be two) to help.

I don't understand how this engine is supposed to get turned over by the puny rotostart that came with it... I have the more recent version of the Savage X 4.6 and there's no gear in the rotostart assembly like with the K 4.6 so what's the problem?

Is my engine still too new?
Does the rotostart sucks that much?
Should I be able to turn the roto-starting shaft by hand because I barely ca with two hands?
Do I worry too much?

Anyways, the thing is starting with a drill so I guess mission accomplished... for now!

Thanks a lot!

 

[Rolex]

It's not uncommon to loosen the glow plug while starting some new engines.
It's easier on the starter with less compression.
Don't add a washer to the glow plug. That will change how it runs.
I'd also do some extra break in time if I were you.